This is a note to let you know that I've just added the patch titled tty: serial: samsung: fix tx_empty() to return TIOCSER_TEMT to the 6.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tty-serial-samsung-fix-tx_empty-to-return-tiocser_te.patch and it can be found in the queue-6.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5130199136ed494bf695241dd046209a2a9227d9 Author: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> Date: Fri Jan 19 10:45:08 2024 +0000 tty: serial: samsung: fix tx_empty() to return TIOCSER_TEMT [ Upstream commit 314c2b399288f0058a8c5b6683292cbde5f1531b ] The core expects for tx_empty() either TIOCSER_TEMT when the tx is empty or 0 otherwise. s3c24xx_serial_txempty_nofifo() might return 0x4, and at least uart_get_lsr_info() tries to clear exactly TIOCSER_TEMT (BIT(1)). Fix tx_empty() to return TIOCSER_TEMT. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> Reviewed-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240119104526.1221243-2-tudor.ambarus@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 3bd552841cd28..06d140c9f56cf 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -987,11 +987,10 @@ static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port) if ((ufstat & info->tx_fifomask) != 0 || (ufstat & info->tx_fifofull)) return 0; - - return 1; + return TIOCSER_TEMT; } - return s3c24xx_serial_txempty_nofifo(port); + return s3c24xx_serial_txempty_nofifo(port) ? TIOCSER_TEMT : 0; } /* no modem control lines */